Xu10 Heads

[cammmy 1]

Just out of interest. Would an XU10J4R head fit on an XU9 block?

 

How much larger is the bore on the XU10's? Could you get steel liners for the XU9 and machine them out to match or is the difference too great?

[John 0]

Even more interesting if a XU10J4RS head would fit.

[James504 12]

Xu10 heads fit. I have a J4RS head on a 1.9 block (not running, in a stalled building stage). Xu9 bore is 83mm, you can go as big as 83.5 with std liners which is around 1927cc. Ive seen aftermarket 85mm liners which give 1997cc. Xu10s are 86mm bore and 1998cc. Cant say if its worth the extra cost or not though, ill leave that upto somebody who knows.

[cammmy 1]

Even more interesting if a XU10J4RS head would fit.

 

I was thinking R as (from what I have read) the inlet valve is about .5mm larger than the RS and also as the ports are smaller you have more scope to have them shaped as there is more metal to work with.

 

To be honest though it would come down to availability really

[welshpug 1,657]

if you intend on getting the head worked over then the XU7 is said to be a better starting point as it shares the same valves as the XU10J4R but has much smaller ports at certain points.

 

having said that, don't get hung up on valve sizes, its about how the complete package works together.

[cammmy 1]

Very good point.

 

It would probably come down to what's available really.

 

I'm not seriously thinking about this (at least for now ) Just thought it would be an interesting discussion.